Reactive intermediates. Part XII. Attempts to form a benzyne–platinum complex

Attempts to prepare and to isolate a benzyne–platinum complex (II), analogous to the known acetylene–platinum complexes (I), by use of three precursors of benzyne are described. A benzyne complex has not been isolated, but evidence is presented for a drastic alteration in the reactions of the benzyne precursors in the presence of platinum(O), in particular the catalysed trimerisation of benzyne to triphenylene.